The overall goal of this research is to develop and apply NMR techniques to assess silicone gel-filled breast implants for biocompatibility, rupture and spread of silicone to distant sites. The growing concern over silicone implants, a serious women's health issue, makes this research clinically relevant. In this proposal, both NMR spectroscopy and MR imaging will be evaluated. Spectroscopy will be used to asses the rupture of silicone implants. In the proposed research, techniques will be optimized for NMR spectroscopy of silicone.. To determine silicone biocompatibility, in vitro multinuclear (1H, 13C, and 29 si) NMR chemical shift information will be obtained from silicones injected in animal tissue, surgically removed silicone gel-filled breast implants, and related tissue from patients. Similarly, in vivo localized NMR spectroscopy (1H,29Si) will be optimized for patient studies. The spectroscopic assessment of silicone distribution will be correlated with histopathology. The proposed research will also optimize and apply chemical shift imaging sequences to assess the NMR characterization of implants and the spatial distribution of silicone. MR images will be compared with mammography and ultrasonography to determine the presence of implant rupture. These results will be confirmed by surgical findings, whenever these are available. Finally a pilot clinical study will be performed in a group of patients to determine if the presence of silicone at distant sites is associated with patient symptomatology. It is anticipated that the techniques developed through this research will have widespread application in women with silicone gel-filled breast prostheses.